1. The Field of the Invention
The invention is in the field of petroleum recovery, more particularly in the field of assessing petroleum production rate and potential for increasing the rate of recovering petroleum from a petroleum reservoir.
2. The Relevant Technology
Petroleum is a critical fuel source and is the life blood of modern society. There is tremendous economic opportunity in finding and extracting petroleum. Due to a variety of technical and geological obstacles, it is typically impossible to recover all of the petroleum contained in a reservoir.
With regard to productivity, operators typically analyze each individual well to determine the rate of petroleum extraction, or well productivity. Operators typically do not understand how to evaluate and understand aggregate well activity and productivity for an entire reservoir or oil field.
Given the high cost of exploration, dwindling opportunities to find new petroleum reservoirs, and the rising cost of petroleum as a commodity, there currently exists a tremendous economic opportunity for accurately assessing productivity of a petroleum reservoir and the potential for productivity gains. Current methods for assessing productivity typically only evaluate individual wells, and there is no method of standard validation for the results over an entire reservoir. Moreover, because production and reservoir depletion continue during the assessment process, the results may in fact comprise obsolete data and assumptions. There is currently no known method for accurately assessing global productivity for a reservoir and the potential for increasing reservoir productivity in a short period of time (i.e., within days, weeks or months rather than years).
While the technology may, in fact, exist to increase the production rate of a petroleum reservoir, an impediment to implementing an intelligent long-term plan for maximizing current output, extending the life of a given reservoir, and increasing total recovery is the inability to accurately assess the health and deficiencies of the reservoir. For example, some or all of the producing wells of a reservoir may show diminishing output, which might lead some to believe the reservoir is drying up. However, the reservoir may, in fact, contain much larger quantities of recoverable petroleum but be under-producing simply due to poor placement and/or management of the existing wells and the failure to know whether and where to place new wells. The inability to properly diagnose inefficiencies and failures and implement an intelligent recovery plan can result in diminished short-term productivity and long-term recovery of petroleum from a reservoir.
In general, those who operate production facilities typically focus on oil well maintenance and may even implement the latest technologies for maximizing well output. They fail, however, to understand the total picture of health and productivity of the reservoir as a whole, which may be serviced by several wells. Wells are difficult and expensive to drill and operate. Once a given number of wells are in place, it may be economically infeasible to drill more wells in order to increase reservoir production (i.e., the marginal cost may exceed the marginal benefit). Moreover, there may be no apparent reason to shut down a producing well even though doing so might actually increase overall productivity and ultimate recovery. The knowledge of when and why to shut down or alter a producing well and/or properly construct a new well often eludes even the most experienced producers and well managers. The failure to properly manage existing wells and/or place and construct new wells can increase capital costs while reducing productivity and ultimate recovery.
The main impediment to maximizing production and recovery from a reservoir is the inability to gather, intelligently analyze, and correctly understand the relevant data. Diagnosing the health of a petroleum reservoir is not straightforward and is much like trying to decipher the health of a human body, but at a location far beneath the earth or ocean. Moreover, the available data may take years to accumulate and assess, yet may be dynamically changing, making it difficult, if not impossible, to formulate and implement an economically and/or technically feasible plan of action. The result is continuing low productivity and long-term recovery from the petroleum reservoir.